margaret brennan is at the nato headquarters in brussels. >> reporter: hillary clinton just finished her last nato meeting as secretary of state. military alliance decided not to intervene in syria to stop the killing that has taken the lives of nearly 40,000 people. they are sending patriot missiles to turkey, to create a shield to protect against potential chemical weapons attack. >> we've made our views absolutely clear to the syrians, to the international community through various channels, public, private, direct, indirect that this is a situation that the entire international community is united on. >> reporter: secretary clinton said the missile shield will only be used for defensive purposes. nato did not discuss a no fly zone or safe haven to protect syrians. for "cbs this morning," margaret brennan, nato headquarters, brussels. >>> in an interview on tuesday, i asked former defense secretary robert gates about the worsening situation in syria and the possibility of the government using chemical weapons against the rebels. >> what should we do in syria if they attempt to mov